Formation sampler



Dec 27, 1966 D. R. WARREN ETAL 3,294,170

FORMATION SAMPLERv 2 Sheets-Sheet l Filed Aug. 19, 1965 0- 688 magg FIG. l

ERNEST H. PURFURST 8\ DAVID R. WARREN I N VENTORS.

AT TORNE Y Dec. 27, 1966 D. R. WARREN ETAL FORMATION SAMPLER Filed Aug. 19. 1963 2 Sheets-Sheet 2 FIG. 3

ERNEST H. PURFURST 8 DAVID R. WARREN INVENTORS.

ATTQRNEY f United States Patent O 3,294,170 FORMATIGN SAMPLER David R. Warren and Ernest H. Purfurst, Houston, Tex., assignors to Halliburton Company, Duncan, Okla., a corporation of Delaware Filed Aug. 19, 1963, Ser. No. 303,104 14 Claims. (Cl. 166-100) The present invention relates to sampling the fluid content of earth formations, and, more particularly, to wireline aparatus for taking samples laterally of a bore hole piercing an earth formation of interest.

Such a device is useful inthat formations about a bore hole at various depth zones may be selectively sampled to determine fluid content. Information derived from such samples is useful, in turn, in evaluating the probable fluid productivity of such zones and, hence, is a valuable aid in selecting from such zones, those having the best production potential for final completion.

Apparatus of this general type adapted for lowering into borehole by means of a wireline and having provisions for utilizing the hydrostatic energy of its sampling environment for various power or actuation requirements is well known and has been long recognized as potentially providing a more facile, efficient, economic means for formation sampling than similar apparatus lowered by means of a tu-bing string, for example. However, the prior art has not enabled the attainment of a sampling success eiciency commensurate with this potential because these devices, in not segregating a true sample of connate fluid from uids which must be purged from the formation before a true sample can be obtained, have not produced fluid samples reliably suitable for quantitative analysis of productive potential.

Further, prior art sampling equipment is generally complex in nature and requires surface control to be exerted at each step of the sampling sequence. These complications and need for control exerted from the surface has maintained the probability of failure at a level such that the reliability of such `devices is of an order which does not normally exceed sixty or seventy percent. It will be appreciated that when a device of this character fails to carry out any step sequence, the particular sampling operation is generally aborted in that a reliable sample is not usually obtained.

Accordingly, it is a principal object of this invention to provide a wireline formation fluid sampler device of improved general effectiveness, efficiency, and reliability and having a new construction and mode of operation not provided in prior art devices.

Another object of the invention is the provision of a formation uid sampler embodying features which result in formation fluid sampling equipment smaller in size than comparable prior art equipment of approximately the same capacity and general capability.

Still another lobject of the invention is the provision of a formation fluid sampler-incorporating a new and improved sample chamber and sample flow :control system.

A still further object of the invention is the provision of a formation fluid sampler device of simplified surface control requirement thru the provision of means to detect the completion of a .step in the sampling sequence and then to automatically effectuate a subsequent step in the sampling sequence.

Other and further objects of t-he invention will be obvious upon an understanding of the illustrative embodiment about t-o be described, or will be indicated in the claims, and various advantages not referred to herein will occur to one skilled in the art upon the employment of the invention in practice.

rice

A preferred embodiment of the invention has been chosen for purposes of illustration and description. The preferred embodiment is not intended to be exhaustive nor to limit the invention to the precise form disclosed. It is chosen and described in order to best explain the principles of the invention and their applications in practical use to thereby enable others skilled in the art to best utilize the invention in various embodiments and modifications as are best adapted to the particular use contemplate-d.

In the accompanying drawings:

FIGURE l is a sectional elevation in diagrammatic form, showing a preferred embodiment of this invention;

FIGURE 2 is a continuation of the lower end of FIG- URE l;

FIGURE 3 is an enlarged, somewhat detailed, sectional view of the pack-olf assembly of FIGURE l, illustrating the same as it would be disposed during movement toward the side wall of the borehole, but not yet engaged therewith;

FIGURE 4 is a somewhat enlarged sectional detailed view showing valve means which may be suitably employed in the system of apparatus of FIGURES 1 and 2; and

FIGURE 5 is a detailed sectional view of a portion of FIGURE 4 showing a modification and indicating the manner of adapting the same for a selective mode of operati-on.

Described generally, a formation sampler device of the present invention, as shown in FIGURES l and 2, comprises a down hole unit generally indicated as 10 and including a body 11 shown suspended from the earths surface within a bore hole 12 by means of a wireline 14 from sheave 17 and winch 1S. The down hole unit 10 is adapted for actuation under control from the earths surface exerted over wireline 14 to move wall engaging mem-bers into engagement with the wall of the bore hole opposite a formation zone of interest and to isolate a portion of such zone and to make a sample therefrom into a sample fluid chamber system provided in the unit.

Actuation of the wall enagaing members is provided for by an actuating system which is adapted to displace wall engaging members outwardly with respect to the body 11 by a rst or actuating stroke powered by a pressurized gas contained in the unit and to Withdraw the wall engaging members from the wall of the bore hole after a sampling operation by a retractive stroke which is powered by the pressure of the column of fluid which normally exists in a bore hole.

It is to be understood that the showing of the Ibore hole 12 as an open hole is merely for purposes of illustration and that down hole unit 10 is equally useful in cased holes penetrating the earths surface, provided an isolation member suitable for employment in casing is substituted for the open hole formation isolation and sealing means illustrated and described.

With further reference to the drawings, down hole unit l 10 principally comprises an actuator and actuator control system 19 and a fluid sample chamber system 80. The actuator and the actuator -control system, housed in the upper part of the device, comprises a cable head section 20, a gas actuator section 30, a formation isolation section 50, and a hydraulic actuator section 75. The fluid sampler chamber system 80, although generally located in the lower portion of the device, overlaps the actuator and actuator control system 19 and includes some components disposed within the formation isolation and hydraulic actuator sections.

Actuator and actuator control system This system serves the purpose of moving the wall engaging members, isolation member 58 and back up plate 58', into and out of engagement with the wall of the bore hole under control exerted from the earths surface over wireline 14. The particular system shown is, in the main, a subject matter portion of a commonly assigned copending application of Robert G. Peter for Flow Formation of Fluid Sampler, Serial No. 247,067, filed December 26, 1962, now Patent No. 3,217,804, issued November 16, 1965. This particular actuator and actuator control system has been selected and adapted for inclusion here principally for the purpose of conveniently providing a complete operative device embodying the present invention. It will be appreciated that other suitably `adapted actuator and actuator control systems may be employed for this purpose instead of the system shown.

The cable head section 20 functions as a means for attaching the downhole unit to the suspending wireline 14, as a -means connecting the electrical power and control circuits (not shown) within the down hole unit to the central conductor wireline 14 (not shown) and asa means for exerting surface control over certain functions of the down hole unit by mechanical tension signal transmitted over the wireline 14. The cable head section is provided with a longitudinally extending compartment 24 and a transversely extending bore 22. A cable socket member extends in sealed slideable engagement through the compartment 24 and further into the transversely extending bore 22 so that both the upper and lower ends of the cable socket member are exposed to bore hole fluids. These end portions are desirably of the same effective cross sectional .area in order that there will be no tendency for the socket to be shifted because of pressure exerted by bore hole fluids. A spring 27 is maintained in biased relation within the compartment 24 and is of a size and bias such that it maintains cable socket member 25 in a normal position biased toward the lower surface of the compartment 24 with a force in excess of that required to support the entire weight of the down hole unit 10.

The cable socket member is provided, at its lower end, with a transversely extending bore 26 normally positioned in substantially coaxial relation with the transversely extending bore 22. The bore 22 4terminates at a blind end which is provided with a threaded coaxial receptacle which communicates with fluid flow passageway 28 within the body 11. A notched break valve 29 is provided in sealed threaded engagement with said receptacle and extends therefrom into the bore 22 and thru 4the bore 26.

The cable socket member 25, in suspending the down ,hole device, normally imposes no load on the break valve.

However, when the down hole 10 is in anchored engagement with the bore hole wall and a predetermined upward tension in excess of the weight of the down hole device is applied from the surface over the wireline, the bias of spring 27 is overcome causing the cable socket member 25 to move upwardly with respect to the valve 29 and break the same and communicate the passageway 28 with bore hole fluid in the transversely extending bore 22. As will appear from the description of the operation of the down hole unit 10, the breaking of valve 29 brings about the retraction sequence of the actuator system.

The gas actuator section 30, disposed immediately below the cable head 20, has the function of providing force and power for urging the wall engaging members 58 and 58 against the wall of the bore hole. Gas actuator section 30 includes a buffer fluid chamber 31 and a gas'expansion chamber 32 spaced apart by a end wall common to each. A piston 31 is disposed in sealed slideable engagement within the buffer fluid chamber 31 and a piston 32 is disposed for sealed slideable engagement within the gas expansion chamber 32. The pist-ons 31 and 32 are mechanically coupled by a rod 33 which extends in sealed slideable engagement thru the common end wall. A rod 33', an extension of rod 33, depends from the lower face of the piston 32 and extends downwardly thru the lower end wall of the chamber 32 in sealed slideable engagement therewith and thence out of the gas actuation section where it is exposed to fluid of the bore hole.

The piston 31 defines a buffer uid space 31 at its rod end within the buffer fluid chamber 31, and a space 31 at its upper end which communicates with fluid flow passageway 28. The piston 32 defines, at its lower end, a gas expansion space 32 and, at its other end, a gas equalization space 32' within the gas expansion chamber 32. The functions of these various spaces will be described hereinafter in connection with description of its operation of the actuator and actuator control system 19. A chamber 34 is provided within the gas actuation section for containing a predetermined amount of pressurized gas for powering the active stroke of the actuated system. Although the passageway connecting chamber 34 with the space 32" is normally blocked by setting valve 36, the passageway is shown in FIG. 1 to be opened and communicating gas to the space 32". The setting valve 36 may be of any type suitable for remote control from the earths surface.

Openings 38 vand 39 are respectively provided at the uppper and lower ends of the gas expansion chamber 32. These openings connect with a valved equalization passageway (not shown) which, although normally blocked, is adapted to open responsive to the opening break valve 29 so that when the break valve 29 is broken, gas pressure is equalized across piston 32. Gas equalization is a step in the retraction sequence of the-actuator operation and will be further discussed in connection therewith.

A hydraulic fluid pressure source 42 is provided within the lowermost portion of gas actuator section 30. As shown, the source comprises a differential area type of fluid pressure intensified piston 43 disposed coaxially around the rod 33 in sealed slideable relation therewith. The piston 43 includes a lower large area section 44 and an upper or small area section 45, which are respectively in sealed slideable engagement with walls of a stepped bore provided in the body 11. With this arrangement, the large area section 44 is exposed to the hydrostatic pressure of bore hole fluid as the device is submerged therein. Bore hole fluid acting on the large area section, exerts an upward force on the piston 43 which, in turn, pressurizes hydraulic fluid above the small area section 45 to a superhydrostatic pressure level. As will appear, this pressurized hydraulic fluid is utilized to move a snorkel member 65 relative to the isolation member 58.

Within the formation isolation section 50, the body 11 bifurcates into laterally spaced longitudinally extending structural members 51 (only one is shown) which define an open space thereabout for housing the wall engaging members 58 and 58', as well as their actuating linkages in their retracted disposition. The portion of rod 33', which extends from the gas expansion chamber 32 between the structural members, is provided with a cross head enlargement 54 which slidably engages longitudinal grooves (not shown) provided in the structural members to give lateral support to the otherwise substantially unsupported rod portion. f

The wall engaging members 58 and 58 are each mounted within the formation isolation section 50 by means of yseparate toggle linkages, each of which comprises a pair of upper -links 56, which are pin-connected at one end to the structural members 51, and a pair of lower links 55, which are pin-connected at one end tothe cross head enlargement 54. The other ends of all links comprising a toggle linkage are 4pinned together by a pin 57 to provide a toggle knee joint, as well as a connection with the associated wall engaging member.

When the cross head enlargement 54 is moved upwardly responsive to admission of pressurized gas to the gas expansion space 32, the wall engaging members 58 and 58 (which are normally maintained in proximity to the structural members 51) are displaced outwardly into engagement with the wall of the bore hole by their respectively associated toggle linkages. The magnitude of the outwardly displacement of the wall engaging members is a function of the angle which the links 55 or 56 make with the rod 33', as are the upward displacement of the rod and the volume of gas expansion space 32". The pressure of a given quantity gas in gas expansion space 32 will, of course, reduce as the volume increases and the total upward force on the rod 33 will be correspondingly reduced. This reduction in force app-lied to rod 33 with vertical displacement, is substantially compensated for by increases in the mechanical advantage of the toggle linkage with increase in the displacement rod 33'. rThus, the forces urging the wall engaging members against the bore hole walls are of substantially constant value over a considerable range of bore hole sizes.

The structure of isolation member 5S is best shown in FIG. 3 in connection with portions of links 55 and 56 of its associated toggle linkage mechanism. In making this connection, the pin 57 extends thru a fluid communication member 61 which comprises a portion of the isolation member 58. The member 61 is fastened to a carrier plate 62 which, in turn, is connected at its peripheral edges with a sealing element 63 (desirably of resilient material) of generally curved configuration having a front face adapted to engage and isolate a portion of the bore hole wall.

The member 61 extends in sealed relation thru carrier plate 62 and in sealed slideable engagement within an insert 64, desirably molded in the material of the sealing element 63. A cylinder 66 is provided in the member 61 in generally coaxial relation with the snorkel member 65 which extends from the cylinder in sealed slideable relation therewith. A piston 67 is provided in sealed slideable relation within the cylinder 66 in abutting relation with one end of the snorkel member 65. The piston 67 is normally disposed such that the snorkel member 65 is in a retracted disposition with respect to the cylinder. Fluid communication member 61 also contains a valve cylinder 68 which, in turn, contains a slide valve element 69 in sealed slideable engagement therein. The slide valve element, at one end, is exposed to the hydrostatic pressures of bore hole fluids and at its second end is exposed to fluid pressure within a passageway 70 in communication with the valve cylinder 66. The cylinder 66, is, in turn, communicated via an opening 71, to the bore of the snorkel member 65. Thus, any fluid pressure existing in the bore of the snorkel member is communicated to the second end of slide valve 69 at all times. The slide valve element 69 normally blocks fluid communication within a passageway, including a flexible section 72 which communicates the pressurized hydraulic fluid above thetsmall area section 45 within the pressure source 42 to the cylinder 66 at that side of the piston 67 therein which is opposite the side thereof in abutting relation to the snorkel member 65. With this arrangement, the valve element 69 is maintained in its normal disposition blocking fluid communication over the passageway 72 when the fluid pressure in the bore of the snorkel member 65 is equal to bore hole pressure. This situation will prevail while the down hole device is being lo-wered into the bore hole and prior to the actuation of the actuation system thereof. However, when the isolation member is brought into sealing engagement with the bore hole wall, the pressure in the b-ore of the snorkel member 65 will become that of formation pressure which is generally different from bore hole fluid pressure. When the isolation member 58 is brought into effective sealing engagement with bore hole wall, the valve 69 will move responsive to the pressure differential established by the seal and open the fluid passageway 72 and admit pressurized hydraulic fluid to the cylinder 66 and effectuate movement of the piston 67. The movement of the piston forces the snorkel member 65 into penetrating engagement with the formation within the area sealed off by the isolation member 58.

Below formation isolation section 50, the longitudinal members 51 emerge with a lower cylindrical portion of body 11 which houses the hydraulic actuator section 75. rThis section functions, not only to power the toggle leakage in retracting the wall engaging members from the bore hole wall, but, together with the chamber 31", functions as a shock absorbing system which moderates any shock forces incident to the setting and retraction of the wall engaging members. The hydraulic actuator section is principally comprised of a chamber 76 and a piston 76 in sealed slideable engagement therein. The rod 33 extends in sealed slideable engagement thru the upper end wall of the chamber 76 and is mechanically coupled to the piston 76'. The piston 76 defines, at its rod end Within the chamber 76 a space 76" filled with a substantially incompressible fluid and, at its other end, a space 76 containing a gas at negligible pressure. The space 76 is communicated with space 31 in the gas actuation section by means of a Arestricted fluid passageway 77 which enables the incompressible fluid initially Contained within space 76 to transfer between lthese spaces as the relative Volumes thereof vary with the vertical displacement of the interconnected assembly comprised of the piston 31', rod 33, piston 32', rod 33', and piston 76.

Assuming the down hole unit 10 has been lowered to a point within a bore hole such that t-he wall engaging members are opposite a formation of interest, the actuating system 19 is actuated by opening the Valve 36 pursuant an electrical signal transmitted from the earths surface over wireline 14. The openingiof the Valve communicates the charge of gas witlhin chamber 34 to space 32" to move piston 32 upwardly in response to gas pressure. interconnected pistons 31 and 76 are also moved in an upward direction. With this movement, the cross head enlargement 54 is displaced upwardly from its initial position, into position shown, to actuate the toggle linkages and force the wall engagement members 58 and 58' respectively into sealed and anchored vengagement with the wall of the bore hole 12 as shown in FIG. 1.

As the wall engaging members are moved into engagement with the bore hole wall, the front face of sealing element 63 will be the first portion of the isolation member 58 to come into Contact. The toggle linkages will continue to move with respect to the body 11 and will tend to compress and conform the sealing element 63 into sealing engagement with the bore hole wall. As the sealing element 63 is compressed, the fluid communication member 61 will be moved with respect to the insert 64. Contemporaneously with these movements and displacements, the sealing element 63 Will establish a seal with respect to the area of the bore hole wall which it contacts and effectively isolate the same from bore hole fluids. At this time a differential pressure will be developed between the bore hole fluids and the formation fluids within the sealed off area such that the slide valve element 69 will automatically shift and effectuate communication of pressurized hydraulic fluid therepast as has ybeen described. The a-dmission of pressurized hydraulic fluid to the cylinder 66 operates to force the snorkel member 65 outwardly with respect to the fluid communication member 61 and into penetrating engagement with the formation to establish a formation flui-d flow path therefrom, into a sample flow line 73 and a passageway 73. The formation fluid sampling phase of the down hole operation would be carried out next by means of the operation of the fluid sample chamber system 80, the operation of which will be described hereinafter. However, assuming for the moment that such formation fluid sampling phase has been completed, the wall engaging members of the down hole unit would next be disengaged from the bore hole wall and retracted into their normal disposition adjacent the longitudinal members 51 so that the down hole unit can be Withdrawn fromthe bore hole. To initiate the retraction of the actuator system 19, a predetermined tension is applied to wireline 14 at the earths surface. This tension in being resisted by the anchored engagement of the wall engaging members with the bore hole wall, works to displace the cable socket member 25 upwardly to accomplish the previously described breaking of the break valve 29. The breaking of the valve permits bore hole fluid to communicate with the space 31, they upper surface piston 31', and to the operating element of the previously referred to valve (not shown) in the equalization line communicating the openings 38 and 39. When the equalization line is thus opened in response to bore hole fluid pressure, the pressure forces of gas across piston 32 are equalized, as has been described. A

The force of bore hole fluid pressure exerted on the top side of piston 31 is communicated by the piston to the buffer fluid in the chamber 31 which causes the fluid therein to transfer back over the restricted passageway 77 into the space 76, whence it was displaced during the actuating stroke of the system. Because the buffer fluid contained below the piston 31 is substantially incompressible, no appreciable mechanical force is directly applied to this piston which is directly effective in motivating a retraction stroke of the actuator system. However, as the buffer fluid transfers back to space 76", as just now described, the pressure in space 76" builds up and acts on the top surface of the piston 76' to exert a tension force in the rod 33 which, in turn, pulls the same and cross head enlargement 54 thereof downwardly to effectuate the retraction ofthe toggle linkages and the wall engaging members.

During the initial portion of the retraction stroke, the carrier plate 62 is moved with respect to the sealing element 63 to withdraw the fluid communication member 61 from the insert 64 an amount suflicient to break the fluid seal normally existing therebetween. 'Ihe breaking of this fluid seal equalizes the pressure within the area sealed off by the sealing element with the pressure of bore hole fluids to facilitate the retraction of the wall engaging members. The retraction is substantially without shock because accelerations are limited in magnitude by the metered transfer of the substantially incompressible buffer fluid over the restricted passageway 77 between the spaces 31 and 76". The retraction stroke of the actuating system, just described, completes the down hole operation so that the unit 10 may be withdrawn from the bore hole by means of wireline 14.

Fluid sample chamber system The fluid sample chamber system 80 functions to receive a first sample portion from within the pore spaces of the formation adjacent the isolated area. The taking of this first sample portion operates to substantially purge a volume of formation of any fluid which may have invaded the same from the bore hole. Then, the fluid sample chamber system takes a second sample portion from the formation within the purged volume. This second sample portion comprises connate fluids to the substantial exclusion of any fluids which may have invaded the formation volume under test. The second sample portion is thus substantially representative of fluids naturally occurring within the formation and is therefore of enhanced value in evaluating the productive potential of the formation under test.

The fluid sample chamber system generally includes upper and lower cylinders, 81 and 82 respectively, and a chamber 83. Fluid separator pistons 84 and 85 are respectively provided in sealed, freely slideable, relation within the cylinders 81 and 82. The piston 84 defines, within cylinder 81, a chamber 86 and a space 87 which are adapted to vary in volume in accordance with the displacement piston 84 in the cylinder 81. The piston 85 similarly defines a chamber 88 and a space 89 within the cylinder 82.

A sample flow passageway v90, including a flow valve 91 and a shut-in valve 9,2, is provided in the body 11 in fluid conducting relation to the sample flow line 73.

The.

passageway connects with branch passageways 93 and 94 by means of a three-Way valve 95, and the branch passageways 93 and 94 respectively connect with spaces 87 and 89. A three-way valve 96 connects the branch passageway 93 with a pressurized gas storage chamber 97 provided within body 11. The chambers 86, 88, and 83 are interconnected by a passageway system including passageways 86 88 and 83 and a valve 98.

A piston displacement sensing device, generally indicated by reference numeral 99, is provided with the body .11 for purpose of measuring the vertical disposition of the piston 84 in the cylinder 81 and providing an electrical signal representative of such measurement for transmission to earths surface where it is recorded with respect to time. Although somewhat schematically shown, the piston sensing device is comprised of a rotary potentiometer with its shaft resiliently biased toward a first or zero rotational position by means of a torsion spring unit mounted on the shaft. A pully is also mounted on the potentiometer shaft and has wound thereon a number of Wraps of actuation cable which, at one end, is fixed to the pully and the other end extends through the upper end wall of `the cylinder 81 and is connected with piston 84. With this arrangement, the displacement of the piston 84 responsive to fluids admitted to the space 87 creates slack in the cable which is concomitantly reeled onto the pully because o-f the torsional or rotational bias provided by the torsion spring. As the cable is lwound onto the pully and as the potentiometer shaft is consequently rotated, the electrical resistance of the potentiometer is varied in a substantially linear manner with changes in dispostition of the piston 84. The variations in electrical resistance in turn, provides for corresponding variations in electrical signal. This signal also defines the volume ofthe chamber 86 and space 87 at any time.

Of the various valves controlling the sample chamber system, flow valve 91 and shut-in valve 92 are two-way valves, respectively normally closed and normally open, andyalves and 96 are three-way valves, as has been indicated, All of these valves are desirably electrically initiated responsive to signal transmitted over the wireline from the earths surface but are desirably actuated by fluid pressure normally available in or about the down hole unit when it is lowered to operating depth. Specific types of such valves, which have been found satisfatcory for this type of application are shown in the commonly assigned copending application of Ernest H. Purfurst, Serial No. 211,980, filed July 24, 1962, now Patent No. 3,254,661, for Fluid Handling System and Apparatus.

As schematically illustrated in FIG. 2, the valve 98 includes a metering orifice 98 and is adapted to selectively meter fluids flowing in the interconnected passageway 83', 86 and 88. With the valve 98 in the position shown in FIG. 2, the valve is disposed to meter fluids displaced from the chamber 86 into the chamber 88. The valve 98 is mechanically interlocked with the valve 95 (schemtically illustrated by the tie 100 in FIG. 2) such that the operation of the valve 98 is positively synchronized ywith the operation of the valve 9S. When the valve 98 is switched, it is adapted to meter fluid from the chamber 88 into the chamber 83 as the piston 85 is displaced upwardly responsive to sample fluid entering the space 89 over the branch passageway 94.

The structure and the relationship of the valves 95 and 98 are shown in greater detail in FIG. 4 wherein the valve 95 is shown to be a Purfurst type three-way valve which normally communicates sample fluids within the passageway 90 to branch passageway 93. The valve 95 includes a valve element which normally provides for the communication between the passageways 90 and 93 and which normally blocks fluid communication to the branch passageway 94. The valve element is maintained in its normal position by a frangible sleeve element 111 which is adapted to fragment pursuant to the firing of a blasting cap 112 pursuant to an electrical signal transmitted from the earths surface. The valve element 110 is provided with an operator extension 113 which extends in sealed slideable relation within an operator bore 114 provided within the body 11. The firing of the blasting cap 112 and the disintegration of the sleeve 111 may be said to merely initiate the operation of the valve 95 in that the actuation of the valve does obtain therefrom, but, rather, is actuated only by external force applied to the operator extension 113. The operator bore 114 within the interior of the body 11, is intersected by the passage- Ways 83', 86 and 88 at spaced points. The operator bore receives the valve 98 in sealed slideable engagement therein with one end in abutting relationship with the operator extension 113 and its other end exposed for wetting by bore hole fluids. With this relationship, the force of bore hole fluid pressure is transmitted by the valve 98 to the operator extension 113 such that movement of the valve element 110 is necessarily accompanied by movement of the valve 98.

The valve 9S is shown as being spool-type construction having a central passageway 98" normally communicating the passageway 86' to the passageway 88 via a metering orifice 115. The valve 98 is provided with a second metering orifice 116 and a port 117 which are adapted, upon shifting of the valve, to communicate the passageway 88 with the passageway 83', via the port 117 and orifice 116. When the valve is thus shifted, the passageway 86 is blocked by a suitable portion of the valve 98. As has been brought out, the shifting of the valve 98 is synchronized with the switching of the sample fluid from branch passageway 93 and space 87 to the branch passageway 94 and space 89. l

Referring again to FIG. 1 and presuming the down hole unit has been placed into actuated anchored engagement with a desired portion of bore hole wall in the manner previously pointed out, and that the piston 84 is in its lowermost position, and that the chamber 86 had been previously filled with a suitable metering fluid, a preferred mode of operation of the sample chamber system is as follows. T-he operation is started yby opening normally closed flow valve 91 pursuant to an electrical signal transmitted from the earths surface thus permitting a fluid sample to flow in the passageway $90 via three-way valve 95 and branch passageway 93 into the space 87. The fluid sample, in entering space 87, works to displace the piston 84 upwardly which, in turn, operates to displace the metering fluid from the chamber 86 via passageway 86', valve 98 and passageway 88 into the chamber 88. This displacement of metering fluid is metered by the choke schematically shownV at 98 in valve 98 (FIG. 2) to control the rate of piston displacement and consequently the rate of flow of the sample entering the space 87.

The displacement of the piston 84 may be monitored at the earths surface by signal transmitted rfrom the piston displacement sensing device 99 and when this signal indicates that the space 87 is of maximum volume and the chamber 86 is -of minimum volume, the rst or formation purging phase of the sample taking operation will have been completed and the metering fluid .previously in the chamber 86 is now in the chamber 88 above the piston 85 and is substantially filling the same.

Next the operator at the surface would initiate the operation of valves 95 and 98 to accomplish t-he switching thereof as previously indicated to divert the fluid in the sample passageway 90 into branch passageway 94 and thence into the space 89, as well as to interconnect the passageway 88 with the passageway 83 in order that the displacement fluid, now in the chamber 88, may be metered into the .chamber 83. Since the formation normally will have been substantially purged during the rst phase of the operation, the sample fluid flowing in the passageway 90 at the commencement of the second phase of the operation normally will be a more representative sample of connate fluid naturally in place within the formation being tested. As the second sample portion enters the space 89, the displacement fluid is again worked by being displaced out of the chamber 88 thru the restriction of valve 98 into the chamber 83.

If, for example, the operator has reason to believe that the formation has been purged of invading fluid before a complete stroke of the piston 84 has been accomplished, he can cut the first phase of sample taking operations short by operating the valve 96 to shut-in the sample flow and admit the charge of gas stored in the space 97 to the chamber 87 to accomplish the full stroking of the piston 84 without reliance on sample fluids to do this work. This accomplishes a quick transfer of the remaining fluid in the chamber 86 into the chamber 88 where, as previously indicated, it may be reworked to meter the flow of fluid sample in the second part of the operation. After the metering fluid has been transferred by the gas, the second phase of the sampling operation would be commenced by the operation of valves 9S and 98 in the manner previously described to secure the desired more representative sample of formation fluid content.

It will be appreciated that this arrangement of sample chambers and system, together with the just-described mode of operation wherein in the same metering fluid quantity is repeatedly worked to obtain a plurality of successive samples, significantly reduces the total amount of metering fluid necessary to obtain any given total volume of fluidsample. This, of course, reduces the total space which must be provided in the down hole device for housing the metering fluid, which, in turn, permits significant reductions in the length of the sampler of any given total sample capacity.

Assuming a sampler device with any given actuator and actuator control system, the length of the device is primarily a function of sampling capacity. In sample cham-ber systems `adapted to employ the water displacement method (such as is described in the commonly -assigned copending application of Brown et al., Serial No. 192,234, filed May 3, 1962, now Patent No. 3,192,742) the sample capacity is about one-half the total chamber capacity. Thus the conventional water displacement systems adapted to take two or three unit volumes of sample will require four or six unit volumes of chamber capacity respectively, whereas with the present arrangement, only three or four unit volumes of sampling capacity will be respectively required. The result is that two or three sample systems in laccord with t-ne present arrangement respectively effect 25 and 30 percent length reductions, as compared to their conventional water displacement system counterparts. Systems in accord with the present arrangement result in length reductions approaching 50% with increasing numbers of `sample capacity units.

It will be readily appreciated that if, instead of the actuator and actuator control system shown, a multi-setting actuator and actuator control system were to lbe combined with the present sample ysystem arrangement to produce a multi-zone sampler device, these savings in length become increasingly important. One multi-setting 'actuator and actuator control system which might be adapted for use in such a multi-zone sampler is disclosed in U.S. Patent No. 2,905,247, granted to Vestamark on September 22, '9. When the sample cham-ber system of the invention is employed in a multi-zone sampler, each unit sample receiving chamber thereof would desirably have associated therewith the valve arrangement and a pressurized gas storage chamber such as is shown intermediate cylinders 81 and 82 in FIG. l. These additional valve arrangements and `gas chambers would normally lbe disposed intermediate adjacent cylinders which function, in part, as unit sample receiving chambers. In the multi-zone sampling application, the Igas storage chambers, together with the ability to transfer metering fluids from one cylinder to yanother without reliance on sample flow to do this work, takes on added importance in that it enables the multiple zone device to make successive multiple zone tests even though one of the successive tests should be a dry one.

In addition to the `foregoing preferred mode of operation of the sample chamber system of the invention, the system is selectively adapted to take first and second formation fluid samples of varying volumes. This capability permits an operator at the earths surface to vary the volumes in a manner so as to maximize the volume of the second or more representative sample. For purposes of selectively obtaining this later type of operation, the v'al've 98 is removed from the operator bore 114 and another valve 118 is `substituted therefor. The valve 118 is mechanically interlocked with the valve 95 in the same manner as has been described in connection with the valve 98.

Referring now to FIG. 5, the valve 118 is shownin its normal position in the operator bore 114 in abutting relation to the operator extension 113. In this normal position the passageway 86 is in communication with the passageway 83 through a central valve bore 119 and metering orifice 120. When the valve 118 moves to the right upon actuation, the passageway 86 is shut off and the passageway 88 is communicated with the passageway 83 via a port 121, valve bore 119 and metering orifice 120. In addition to this change out of the valfve associated with the valve 95, it is desirable that both of the chambers 86 and 8S 'be initially filled with metering fluid to achieve the selective or Ialternate mode of operation of the system which is as follows.

Presuming that the down hole unit is in sealed anchored engagement with the wall of the bore opposite a zone of interest, the flow valve 91 would be open to ad-v mit a first sample portion to the space 87. As this first sample portion enters the space 87 a proportionate volume of the metering fluid in the chamber 86 will be throttled through the valve 118 into the chamber 83 via the passageway 83. As the sample enters the down hole device a fluid property, e.g., fluid resistivity, may be monitored by the operator at the earths surface. When the monitored property becomes constant in value, indicating that representative sample fluids are flowing in the passageway 90, the operator may operate the interlocked valves 95 and 118 to connect the flowing sample to the space 89 via the branch passageway 94 and, at the same time, communicate the metering fluid in the chamber 88 with the orifice 120. Since the formation will have been substantially purged with the taking of the sample in the first sample chamber, the sample entering the space 89 will be the desired more representative fluid. The volume of the first sample will be a function of the depth to which bore hole fluids have invaded the formation and when this invading fluid has been purged, the remaining capacity of the sampling system in this mode of operation will be lled with the desired more representative sample. With this latter mode of operation it will be apparent that the time required for purging the formation. will be minimized, and, the volume of the second or connate fluid sample will be maximized.

Thus, it has been seen that the present invention provides a new and improved formation fluid sampler which results in improved sampling performance as compared to prior art formation fluid sampling equipment. It has further been seen that this improved performance arises, in part, from a highly efficient sample chamber system which works to maximize the fluid sampling capacity of any given device in which it may be embodied and which minimizes the size of such a device. Further, it has been seen that the sample chamber system of a device embodying this invention is adapted for eective employment, not only in single zone test equipment, but in multi-zone equipment, as well. It has still further been seen that the device of the invention, through the embodiment of new and simplified controls, results in formation fluid sampling apparatus having reduced surface control requirements, as compared to conventional apparatus andvthat this, in part, accounts for the enhanced reliability and effectiveness of this equipment.

As various changes may be made in form, construction, and arrangement of the elements herein disclosed without departing from the spirit or scope of the invention, and Without sacrificing any'of its advantages, it is to be understood tha-t all matters herein are to be interpreted as illustrative and not in any limited sense.

What is claimed is:

1. In a well testing apparatus for use in a bore hole containing a column of fluid at a pressure different from the fluid pressure of an adjacent earth formation, the combination of: a support adapted for passage thru a bore hole; a fluid sample chamber in said support; a sealing member mounted on said support and including a front surface adapted to engageand isolate a portion of the bore hole wall and seal the same with respect to bore hole fluids; said sealing member having a port eX- tending thru said front surface; means connected to said support for moving said sealing member into contact with the bore hole wall; a source of hydraulic fluid under pressure in said support; a probe moveable thru said port and having a central bore for receiving a sample of formation fluid; a fluid flow passageway communicating the sample fluid received within said probe bore with said sample chamber; motive means connected with said probe for moving said probe thru said port into penetrating engagemen-t with the formation within the portion of bore hole wall isolated by said sealing member; a fluid channel connecting said source with said motive means for supplying hydraulic fluid under pressure thereto; valve means normally blocking said fluid channel adapted to open and admit hydraulic fluid to said motive means in response to the establishment of a fluid seal between said sealing member and the bore hole wall.

2. In a formation sampling device for use in a bore hole containing a column of fluid at a pressure different from the fluid pressure existing within an adjacentl earth formation, the combination of: a support adapted for passage thru a bore hole; a fluid sample chamber in said support; a sealing member mounted on said support and including a front surface adapted to engage and isolate a portion of the bore hole wall and seal Ithe same with respect to bore hole fluids; said sealing member having a port extending thru said front surface; means connected to said support for moving said sealing member into contact with the bore hole wall; a source of hydraulic fluid under pressure in said support; a probe moveable thru said port and having a central bore for receiving a sarnple of forma-tion fluid;.a fluid flow passageway communicating the sample fluid received within said probe bore with said sample chamber; motive means operatively connected with said probe and fluidly connected with said source for moving said probe thru said port into penetrating engagement with the formation within the portion of bore hole wall isolated by said sealing member responsive to application of hydraulic fluid pressure from said source; valve means normally blocking fluid communication between said source andmotive means adapted to open and admit hydraulic fluid to said motive means in response to the different between bore hole fluid pressure and formation fluid pressure being applied thereto subsequent to the engagement of the sealing member with the bore hole Wall and the ensuing isolation of an area of the bore hole wall.

3. In a fluid sampling device for use in a bore hole containing a column of fluid at a pressure different from the fluid pressure of an adjacent earth formation, the combination of: a support adapted for passage thru a bore hole; a first fluid chamber in said support; a sealing member mounted on said support and including a front surface adapted to engage and isolate a portion of the bore hole wall and seal the same with respectto bore hole fluids; said'sealing member having a port extending thru said front surface; means connected to said support for moving said sealing member into contact with the bore hole wall; a second fluid chamber in said support; a probe moveable thru said port and having a central bore for receiving a sample of formation fluid; a first fluid passageway communicating between said probe bore and said first fluid chamber; a motive means connected with said probe for moving said probe thru said port into penetrating engagement with the Wall of the bore hole within the portion thereof isolated by said sealing member; a second fluid passageway communicating said second fluid chamber with said motive means; valve means normally blocking one of said fluid passageways adapted to open and establish fluid communication therethru in response to the establishment of a fluid seal between said sealing member and the bore hole wall.

4. A device for obtaining samples of the fluid content of earth formations traversed by a bore hole comprising: :a support adapted to Fbe lowered within a bore hole from the surface of the earth to a location adjacent an earth formation from which a fluid sample is desired; means on said support, including a fluid inlet, for engaging an area of formation comprising the bore hole Wall and for establishing communication between said inlet and fluids contained within said formation; first and second cylinders in said support, a piston in sealed slideable relation Within each of said cylinders; each piston dividing its cylinder into a chamber and a space; valved pa-ssage means interconnecting said rst, -second and third chambers; said first chamber containing a quantity of substantially incompressible fluid; a normally closed sample fluid passageway connecting said fluid inlet with said space within said first cylinder; means for opening said sample fluid passageway to provide fluid flow and pressure communication therethru from said fluid inlet into said first cylinder space whereby any sample duid entering said first cylinder space operates to displace the piston therein to reduce the volume of said first chamber and to displace the incompressible fluid therein through said passage means into lone of the other of said chambers.

i The device of claim 4 wherein said one of the other of said chambers is said second chamber.

6. A device for `obtaining a plurality of successive samples of the fluid content of earth formations traversed by a bore hole comprising: a support adapted to be lowered within a bore hole from the earths surface to a location adjacent an earth formation from which fluid samples are desired; means on said support, including a fluid inlet, for engaging an area of formation comprising the bore hole wall and for establishing communication lbetween said inlet and fluids contained within said formation; first and second cylinders in said support, `each having first and second end walls; a piston in sealed slideable relation withineach of said cylinders normally disposed toward the first end wall thereof; first and second chambers respectively defined Within said first and second cylinders between the second end wall thereof :and the piston associated therewith; a third chamber in said support; valved passage means interconnecting said first, second and third chambers; said first chamber containing a quantity of substantially incompressible fluid; a normally closed sample fluid'passageway connecting said fluid inlet with said first cylinder intermediate said first end wall thereof and the piston therein; a normally closed branch passageway connecting the sample fluid passageway with said second cylinder intermediate said first end wall thereof and the piston therein; means for opening said sample fluid passageway to provide fluid flow and pressure communication therethru from. said fluid inlet into said first cylinder, whereupon sample fluid entering said first cylinder operates to displace the piston therein toward the second end wall thereof and thereby reduce the volume of said first chamber and transfer the incompressible fluid in said first chamber through said passage means into said second chamber; and valve means at the juncture of said sample fluid and branch passageways 'for shifting said vfluid flow and pressure communication from said first cylinder to said branch passageway and second cylinder responsive to surface control; whereupon said shifted fluid flow and pressure communication direct-s sample fluid into said second cylinder, displacing the piston therein toward the -second end wall thereof to thereby reduce the volume of said second charn- 'ber .and transfer the incompressible fluid therein through said passage means into said third chamlber.

7. In a fluid sampling device for use in a bore hole containing -a column of fluid at a pressure different from the fluid pressure of an adjacent earth form-ation, the combination of: a support adapted Ifor passage thru a -bore hole; a cavity in said support; a sample inlet member mounted on said support and including a rear surface and a front surface adapted to engage and isolate a portion of the bore hole wall and seal the saine with respect to bore hole fluids; means connected to said support for moving said sample inlet member laterally with respect thereto into contact with the bore hole wall; a fluid passageway communicating between said sample inlet member and said cavity; and valve means in said passageway including a flow control element and first and second ducts respectively communicating any fluid pressure acting on said rear and front surfaces to said flow control element and lapplying force thereto, said flow control element adapted to shift from a normal disposition maintaining a first flow condition in said passageway to an actuated disposition establishing a different flow condition in said passageway responsive to a substantial difference in fluid pressures acting on said rear and front surface and applied to said flow control element via said ducts.

8. A device for obtaining samples of the fluid content of earth formations traversed by a bore hole comprising: a support adapted to be lowered within a :bore hole from the surface of the earth towa location .adjacent an earth formation from which a fluid sample is desired; means on said support, including a fluid inlet, for engaging an area of formation comprising the bore hole wall and for establishing communication betweentsaid inlet and fluids contained within said formation; first, second and third chambers in said support; valved passage means interconnecting said first, second and third chambers; said first chamber containing ia quantity of substantially incorn- -pressible fluid; a normally closed sample fluid passageway interconnecting said fluid inlet with said first chamber; means for opening said sample fluid passageway to provide fluid flow .and pressure communication therethru from said fluid inlet into said first chamber, whereby any sample fluid entering said first |chamber operates to displace the incompressible fluid therein through said passage means into one of the other of said chambers.

9. The device of claim 8 wherein said one of the other of said chambers is said second chamber.

10. A device for obtaining a plurality of successive samples lof the fluid content of earth formations traversed by a bore hole comprising: a support adapted to be lowered within a bore hole from the earths surface to a location adjacent earth formations from which fluid samples are desired; means on said support, including a fluid inlet, for engaging an area of formation comprising the bore hole wall and for establishing communication between said inlet and fluids contained within said formation; first, second and third chambers in said support; valved passage means interconnecting said first, second and third chambers; said first chamber containing a quantity of substantially incompressible fluid; a normally closed sample fluid passageway connecting said fluid inlet with said first chamber; said sample fluid passageway including a normally closed branch passageway connecting the sample fluid passageway with said second chamber; means for opening said sample fluid passageway to provide fluid flow and pressure communication therethru from said fluid inlet into said first chamber, whereupon sample fluid entering said first chamber operates to displace the incompressible iluid therein through said passage means into said second chamber; valve means at the juncture of said sample uid and branch passageways for shifting said sample fluid flow and pressure communication from said tirst chamber to said branch passageway and second chamber responsive to surface control, whereupon said shifted uid flow and pressure communication directs sample fluid into second chamber displacing the incompressible iluid :therein through said passage means into said third chamber.

11. A device for obtaining multiple samples of the fluid -content of earth formations traversed by a bore hole comprising: a support adapted to be lowered within a bore hole from the surface of the earth to a location adjacent earth formations from which uid samples are desired; means on said support, including a uid inlet, for engaging an area of formation comprising the bore hole wall and for establishing communication between said inlet and fluids contained within said formation; a plurality of sample chambers in said support; a displacement iluid receiving chamber in said support; valved passage means interconnecting said plurality of sample chambers with said displacement uid receiving chamber; a first chamber of said plurality containingv a quantity of substantially incompressible displacement uid; a normally closed sample fluid passageway interconnecting said fluid inlet with the last-mentioned sample chamber; means for opening said sample uid passageway to provide uid flow and pressure communication therethru from said fluid inlet into said last-mentioned sampler chamber, whereby any sample uid entering the same operates to displace said incompressible displacement luid therein through said passage means into a second sample chamber of said plurality; a second normally closed sample fluid passageway interconnecting said uid inlet with the last-mentioned sample chamber; and means for opening the second normally closed sample passageway to provide liuid ow and pressure communication with the last-mentioned chamber, whereby any sample fluid entering the same operates to displace said incompressible displacement uid therefrom through said passage means into said displacement uid receiving chamber.

12. The device of claim 11 wherein said sample chambers of said plurality, as well as said displacement uid receiving chamber, are all of substantially the same lluid volume capacity.

13. A device for obtaining multiple samples of the uid content of earth formations traversed by a bore hole comprising: a support adapted to be lowered within a bore hole from the surface of the earth to a location adjacent earth formations from which fluid samples :are desired; means on said support, including a fluid inlet, for engaging an area of formation'comprising the bore hole wall and for establishing communication between said inlet and fluids contained within said formation; a plurality of sample chambers in said support; a displacement fluid receiving chamber in said support; valved passage means interconnecting said plurality of sample chambers with said displacement fluid receiving chamber; a lirst sample chamber of said plurality containing a quantity of substantially incompressible displacement uid; a normally closed sample fluid passageway interconnecting said fluid inlet with said first sample chamber of said plurality; means for opening said sample Huid passageway whereby any sample fluid in said uid inlet is admitted to said last-mentioned sample chamber, whereupon the pressure force of uid entering the same may operate to displace said incompressible displacement fluid therein through said passageway means into a se-cond sample chamber of said plurality; means in said support for securing the displacement of said incompressible displacement of fluid over said restricted passageway to said second sample chamber of said plurality in response to surface signal, in event that the sample fluid communicated to the first chamber of said plurality is ineiective to do so; a second normally closed sample uid passageway inter-connecting said fluid inlet with the second sample chamber of said plurality; and means for opening the last-mentioned passageway to provide lluid iiow and pressure communication with the last-mentioned chamber, whereupon any sample Ifluid entering the same operates to displace said incompressible displacement iluid therefrom through said passageway means into said displacement uid receiving chamber.

14. The device of claim 13 wherein said means for securing the displacement of said incompressible displacement iluid through said passage means to said second sample chamber of said plurality in response to surface signal includes a chamber filled with pressurized gas and interconnected with said first sample chamber of said plurality by a passageway :blocked by a normally closed valve yadapted to open in response to electrical signal transmittedfrom the earths surface.

References Cited by the Examiner UNITED STATES PATENTS 2,612,346 9/1952 Nelson 166-100 X 2,640,542 6/1953 Brown et al 166-100 X 2,965,176 12/1960 Brieger et al 166-100 2,992,631 7/1961 Fallows 137-609 X 3,010,517 11/l961 Lanmon 166-100 3,079,793 3/19-63 LeBus et al 166-100 X CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

8. A DEVICE FOR OBTAINING SAMPLES OF THE FLUID CONTENT OF EARTH FORMATIONS TRAVERSED BY A BORE HOLE COMPRISING: A SUPPORT ADAPTED TO BE LOWERED WITHIN A BORE HOLE FROM THE SURFACE OF THE EARTH TO A LOCATION ADJACENT AN EARTH FORMATION FROM WHICH A FLUID SAMPLE IS DESIRED; MEANS ON SAID SUPPORT, INCLUDING A FLUID SAMPLE IS DESIRED; MEANS AREA OF FORMATION COMPRISING THE BORE HOLE WALL AND FOR ESTABLISHING COMMUNICATION BETWEEN SAID INLET AND FLUIDS CONTAINED WITHIN SAID FORMATION; FIRST, SECOND AND THIRD CHAMBERS IN SAID SUPPORT; VALVED PASSAGE MEANS INTERCONNECTING SAID FIRST, SECOND AND THIRD CHAMBERS; SAID FIRST CHAMBER CONTAINING A QUANTITY OF SUBSTANTIALLY INCOMPRESSIBLE FLUID; A NORMALLY CLOSED SAMPLE FLUID PASSAGEWAY INTERCONNECTING SAID FLUID INLET WITH SAID FIRST CHAMBER; MEANS FOR OPENING SAID SAMPLE FLUID PASSAGEWAY TO PROVIDE FLUID FLOW AND PRESSURE COMMUNICATION THERETHRU FROM SAID FLUID INLET INTO SAID FIRST CHAMBER, WHEREBY ANY 